Power tool machine



May 11, 1943. MOORE 7 2,318,956 POWER TOOL MACHINE Filed Aug. 2, 1940 2Sheets-Sheet l May 11, 1943. I o; MOORE 2,318,956

POWERTOOL MACHINE Filed Aug. 2, 1940 .2 Sheets-Sheet 2 Patented May 11,1943 UNHTED STATES PATENT OFFICE POWER TOOL MACHINE Omer Moore,Corvallis, Greg. Application August 2, 1940, Serial No. 349,827

' v Claims. (01. 1 13-47) This invention relates to a machine forproducing straight line movement of a power driven tool, and hasparticular reference to a machine in which a rotary tool such, as acircular, saw, sanding disc, emeryfwheel, or the like, is mounted forreciprocatory motion in a horizontal straight line, the movement of thetool carrying frame being manually controlled by means of mechanismwhich the operator may actuate with his foot.

The illustrated embodiment of the invention relates to a machine forimparting straight line movement to a cut-off or trim saw, such a ma-.chine being adapted, however, for various uses. For example, because themachine is'so designed that the saw travels in a horizontal straightline and will cut at a predetermined elevation throughtout the fulllength of its stroke, it may be used for grooving or dadoing relativelywide or long pieces, such as table tops, moldings, and the like.Moreover, because the saw travels in a straight line, instead ofswinging through an arc, cut-01f saws of much smaller diametermay beused in place of the larger diameter saws usually mounted on a swingingframe for doing the same Work. For example, a saw 36 inches indiametermounted on a machine embodying the present invention will cutthrough a timber 12 inches in thickness and of indefinite width,

, and permit the use of aneight inch collar on the Essentially, the toolcarrying frame is provided at the base with arcuate rocker surfaces,with the arbor mounted coaxially with the arc of the frocker surfaces.By reason of this construction, when the frame isrocked on-the arcuatebearing surfaces the arbor advances in a straight line. Either manual ormechanical devices may be inlength of travel of the tool. The inventionis es pecially suited, however, for use in small shops, "and the frameis preferably designed to be rocked corporated in the mechanism forrocking the ,frame, as well as mechanism for controlling the manually bythe operator by means of mecna-' nism which he may actuate with hisfoot.

Power to drive the tool may be furnished by an electric motor so mountedon the frame. as to serve as a weight to rock the frame back at theconclusion of each cutting stroke, although power may be transmitted tothe arbor from another source, and any one of several means may beadopted to restore the frame to its normal rest position each time afterit completes a certain operation.

It is, therefore, an object of the invention to provide a mechanism formounting and operating a rotary tool and rendering it responsive to thewill of the operator, whereby the capacity of the machine is greatlyincreased and the ease of operation considerably augmented.

It is a further object of the invention to provide a swing-type framefor a rotary tool so designed that the tool travels in a,,horizontalstraight line throughout the full length of its stroke.

" A further object of the invention is to provide a swing-type travelingsaw' which may be used for dadoing or grooving relatively wide or longpieces. T

It is a further object of the invention to provide a sawing machine inwhich the saw carrying frame is designed to be rocked manually by theoperator by means of foot actuated mechanism, leaving the hands free tomanipulate the stock. 7 I

It is a further object of the invention to provide a saw frame for atraveling saw, having arcuate bearing surfaces, with the saw arbormounted on the axis of the arc, whereby, by rocking the frame, the sawis caused to travel in a straight line; together with means for holdingtheframe within predetermined bounds.

Other objects of the invention are to provide a machine of few parts,which may easily be assembledor dismantled, and transported to newfields of operation; and which provides the widest possible margin ofsafety and convenience in operation. i

Additional objects and advantages-of the invention will become apparentas the description proceeds in connection with the'accompanyingdrawings, it being understood that the drawings -towithout departingfrom the spirit or scope of the invention; and I deem myself entitled toall such changes andmodlfications-thereof as fall Figure 3 is aperspective view of a portion of the track for the tool carrying frame.

Figure 4 is a. side elevation of a cut-off saw employing the presentinvention, illustrating a modification of the mechanism for holding thesaw carrying frame within predetermined bounds.

Figure 5 is a side elevation, partly in section, of an embodiment of theinvention, showing an adaptation of treadle means for rocking the toolcarrying frame.

Figure 6 is a sectional elevation taken transversely of the machine onthe line 66 of Figure 5.

Figure '7 is a plan view of the apparatus illustrated in Figure 6.

Figure 8 is a fragmentary detail of the arbor, showing a modification ofthe power take-off for operating the tool.

Figure 9 is a fragmentary sectional elevation of the track for the sawcarrying frame, taken on the line 9-9 of Figure 4.

As illustrated in the drawings, the mechanism comprises a horizontalbase I and uprights 2 which support a table top 3 upon which is laidmaterial to be worked. The table top 3 may be supported upon cross framemembers 5, through which are received the depending ends of spindles 4secured to the underside of the table. A nut 6 threadedly engages eachspindle and transfers the weight of the table to the frame. member, alock nut being provided for an obvious purpose. The table top 3 isequipped with a slot 8 to accommodate the working run of a rotary tool9, such as a circular saw.

Mounted longitudinally of the machine upon the base 2 are spacedparallel tracks l0, and rockably supported upon these tracks I0 is atool carrying frame II. The tool carrying frame H comprises side membersl2, each of which is provided at the lower edge with an arcuate rockersurface for cooperatively bearing upon the corresponding track and whichside members may, for example, be made in the form of a sector of acircle. In the several illustrated embodiments of the invention the endsof each side member I2, corresponding to the radii of the sector, aredisposed at an angle to each other of 60 or more, depending upon thelength oftravel to be imparted to. the tool. It will readily beunderstood that the longer the length of the radii of the rockersurfaces the shorter need be the are thereof to provide the same lengthof saw travel. Each of the side members i2 is equipped with sprocketteeth l3 upon its arcuate rim. which mesh with sprocket teeth upon atleast one of the tracks III. A shaft or arbor l4, upon which is mountedthe rotary tool or saw 9, is suitably journaled in the frame Ilcoaxially with the arc of the rocker surfaces. Thus it will be seenthat when the tool carrying frame Ii is rocked upon the tracks ID thetool 9 will be caused to travel through a predetermined pathway in ahorizon tal straight line.

Power to drive the tool 9 is transmitted to the arbor by means of a belti5 trained around a pulley l6 mounted on the arbor, and around a pulleyI! secured to the armature shaft of an electric motor 18 mounted on abase l9 fixed between the sides l2 of the frame I l at what may betermed the rear edge of the sector.

It will be noted that the motor is mounted at a point adjacent thearcuate rim of the frame and near the rear end of the rockers, in whichposition it resists by force of gravity the movement of the frame H awayfrom the position illustrated in full lines in Figure 1, the resistingforce increasing with the length of travel of the tool. By mounting themotor upon the frame ll in the position just described, it serves as aweight for resisting forward movement of the frame, and for restoringthe frame I l to a starting position each time after the tool hascompleted a certain operation. It will be appreciated, of course, thatin place of the motor l8, any suitable weight may be mounted on the basel9 between the sides I2 of the tool carrying frame H, power to drive thetool being transmitted from another source (not shown) to a pulley 20mounted on the arbor id in the manner illustrated in Figur 8. Theoperation of a weight mounted at the rear end of the rockers (whether ornot the weight be supplied by the presence of the motor I8) is to tendnormally to maintain the tool 9 and the tool carrying frame H in arearward position. The gist of the invention, however, is the provisionof a rockable tool carrying frame which operates to move the tool in astraight line at a predetermined elevation, and it is not deemed to beessential that the tool carrying frame be restored to a startingposition each time after the completion of a certain operation by meansof a weight positioned in line with one leg of the frame. It is intendedto be within the purview of the present invention that the tool carryingframe may be rocked by any suitable mechanism made for that purpose.

In Figure 3 is shown a fragmentary detail of a track l0 comprising atimber 22 having a multiplicity of short pins 23 projecting horizontallyfrom one side thereof which form a track over which the tool carryingframe H is rocked, the rim thereof being designed to engage with thepins 23 and hold the frame from retrograding movement during a cuttingoperation. The upper surface of each timber 22 is rounded, and the pins23, projecting inwardly toward the timber forming the other rail of thetrack, are preferably elevated somewhat, above the floor. Thisconstruction provides; a track which is easily kept free ofaccumulationsof sawdust and the like, and insures accurate, smoothv action of thetool carrying frame. The rim of each side member i 2 is provided with aflange 2 I, the flanges being provided with spaced notches 24 forengaging said pins 23 as the frame, is rocked. The notched flanges aresimilar to a. sector gear, and the pins 23 form a rack, thisconstruction preventing creeping of the tool carrying frame, and holdingthe tool in proper alignment.

A modification of the track structure for the tool carrying frame isillustrated in Figures 4 and 9. The structure there, shown isparticularly desirable when the invention is to be embodied in a cut-offsaw for severing heavy timbers, as in a sawmill. The constructionillustrated comprises spaced apart parallel timbers 25 and 26 which forma track for the saw carrying frame 21. At least one of the timbers, 26,is so shaped that its upper surface, in cross section, is in the form ofan inverted, truncated V. The corresponding 'arcuate rim portion 28 ofthe saw carrying frame '2l includes a flange 29, the under side of whichis recessed so as to provide running engagement as to have runningengagement'with the track 30.

For holding the saw carrying frame 21 (Figures 4 and 9) withinpredetermined bounds and for "preventing creeping thereof during asawing operation, the end of a cable 32 is aflixed to each end of thesaw carrying frame, the cable underlying the frame 21 and being attachedto one of the frame members at the opposite end of the machine by meansof an eye bolt 33, passing therethroug'h. Tension on the cable 32 may beadjusted in the well known manner by means of a nut 34 threaded onto theprojecting end of 1 the eye'bolt. In the illustrated embodiment of theinvention the cables 32 lie in closely spaced parallel relation, theirworking runs being received in suitable recesses in a guide block 35disposed centrally of the rim of the saw carrying' frame 21.

Figures 1 and 2 illustrate a simple application of the presentinvention. Mounted upon the arbor [4 of the frame I l is a circular saw9, the device being particularly useful as a small shop saw or onecapable of being moved from place to place in connection withconstruction work. Extending transversely of the saw carrying frame IIand interconnecting the side members I2-l2 is a cross frame member 45positioned adjacent the lower extremity of the front leg of the frame.The cross frame member 45 is so positionedas to be used as a treadle forrocking the frame, and an operator may make use of the device by thesimple expedient of pressing upon the cross frame member 45 with hisfoot.

The motor being energized to drive the saw, suflicient pressure isexerted upon the cross frame member 45 to overcome the force of gravityexerted by the motor l8 and cause the frame II to be rolled forwardlyupon the tracks I0. Thus the saw 9 is moved forward in a horizontalstraight line to do the work required of it. Upon completing the sawingoperation, the operator removes his foot from the cross frame member 45,whereupon the weight of the motor l8 causes the frame to roll backwardand resume its normal or rest position, from which position it may againbe rocked forwardly to commence another sawing operation.

Referring now to Figures 5 and 6, the saw carrying frame II is rockedupon the tracks l through the action of a treadle 36 affixed to theforward or free end of a bell crank 31 pivoted at 38 and connected bymeans of a link 39 to an arm 4|]. One end of the arm 40 is pivotallymounted on a stud shaft 4| fixed to the frame of the machine, the otherend being deflected as shown in Figure 6 to cause it to lie in paralleljuxtaposition to the adjacent side member l2 of the saw carrying frame,to which it is loosely pivoted as by a longitudinally disposed slot 42and a through bolt 43 threaded into an aperture provided therefor in thesaw carrying frame ll.

Preferably, the stud shaft 4|, which is the pivotal point'for: theJarm40, extends at right angles from a point substantially midway betweenthe limits of travel of the saw, the'deflected end of the arm 40 beingpivoted to the saw carrying frame I l'at a point along the-center radiusof the frame, by reason of which construction the frame Il may be rockedfrom the rest positionillustrated in'full lines in Figure 5 to the endof the full stroke of the saw illustrated in dotted lines in Figure 5with the least possible expenditure of effort. By this means the maximumleverage to be exerted by the treadle 36 is provided 'for'under allworking conditions.

.JIn operatiomthe motor l8 being energized to drivethe saw 9,theoperator standing in front 'ofthe machine feeds the materialto be sawedupon the table top 3 and presses the treadle 36 with his foot. Theeffect is to rock the saw carrying frame ,ll forwardly from its restposition to cause the saw 9 to advance from its position shown in fulllines in Figure 5 toward the position therein shown in dotted lines. Asthe treadle 36 is depressed and the frame I l rocked forwardly on thetracks l0, the weight ofthe motor I 8 is lifted against the force ofgravity, the resistance offered thereby increasing with the length oftravel of the saw. At the completion of any certain sawing operation,the movement of the saw carrying frame is suddenly and forciblyreversed, and the frame restored to its normal very readily to guards,and to devices for removing sawdust. A further advantage of theinvention is that a machine employing'its use is extremely mobile. Byremoving the table to'p 3 the machine can be'disassembled into threeparts merely by lifting them apart, so that one man can easily move avery powerful rig.

It is intended that it shall be understood that although the particularembodiment of the invention herein illustrated and described isprimarily designed as a shop saw, with the tracks and table topconstituting component parts of one machine, the device is alsoapplicable for use as a cut-off saw in a sawmill. Moreover, it is notintended that the application of the device shall be limited to the useof any particular type or kind of tool, or for operation on anyparticular kind of material, the invention being susceptible for usewherever it is needful to move a tool in a horizontal straight line. Itis intended that the invention may be used either in its entirety or inpart, and either with or without modifications, without departing fromthe spirit of the invention, and I deem myself entitled to all such usesand modifications and/or variations as fall within the spirit and scopeof the claims hereto appended.

Having now described my invention and in.

what manner the same may be used, what I claim as new and desire toprotect by Letters Patent is:

1. A power tool comprising a support, spaced parallel tracks on saidsupport, a frame having a pair of arcuate bearing surfaces mounted on'saidtracks for limited rocking movement there upon; a tool arbor'mounted on said frame-too: axially withthe axi's of the arcof saidbearing surfaces whereby rocking movement of said frame will Texert" a'straight line' motion to said arbor, a motor for drivingsaidarbor,lsaidrmotor 'beingmo'unted on said frame xtoward .oneiend of saidbearing surfaces whereby theweight of said motor rocks saidframe to apredetermined position, and means "for rocking'saidfranie'away from saidpredetermined position to moveisaid tool arbor into operative engagementwith a workpiece.

2. A power tool comprising a support, a pair of spaced apart paralleltracks extending longitudinally on said support, a frame having meansdefining a pair of arcuate rockers, said rockers being arranged uponsaid tracks for'limited rocking movement thereupon, an arbor mounted onsaid frame coaxially with the axis of the arc of said rockers, saidframe being wholly supported and guided by said tracks, said arbor beingguided in a predetermined straight line solely 'by engagement of saidrockers with said tracks upon rocking movement of said frame, manuallyoperable means for rocking said frame in one direction, and acounterweight mounted onsaid frame for rocking said frame in theopposite direction.

3. A power tool comprising a support, a pair ,of spaced apartlongitudinal tracks arranged parallel to each other on said support, aframe having a pair of opposite side members defining a pair of arcuaterockers arranged upon said tracks for limited rocking movementthereupon, means for preventing slipping of said frame relative to saidtracks, an arbor journaled upon said side frame members coaxially withthe axis of the arc of said rockers, a saw mounted on said arbor, atransverse frame member rigidly secur- .ing together said side framemembers, a motor supported on said transverse member toward one end ofsaid rockers for rocking said frame in one direction upon said tracks,means for rocking .said frame in the opposite direction, said framebeing wholly supported and guided by said tracks straight line fraine.

whereby said saw-is guidediin a predetermined movement rocking of saidA. Appower toiol oonrprisinsa' Su port; a pair of spaced #apart'longitudinal 'tragks" arran ed parallel toiach' other'on said support;a'wframe having .a pair of opposite side members definin a pair ofarc'uate rockers arranged-1 90111 'Lsai tracks for limited rockingmovement thereupon, meansior preventing slipping or said af amerrelativeto said tracks, an arbor journaled upon' said side frame membersooai'iiallywith the axis of the arc of said rockers and extendingbetween said side members, a saw-mounted on :said arbor and between saidside members, a 'tranSVfl-se frame member rigidly securing together saidside frame members, .a motor supported on said transverse member towardone end ,of said rockersfor rocking said frame in one direction uponsaid -tracks,'means for rocking said frame in the opposite direction,said frame being wholly supported and guided by said tracks whereby saidsaw is guided in a predetermined straight line movement upon rocking ofsaid frame.

5. A power tool comprising a support, a pair of longitudinally spacedapart tracks mountedin a parallel relation on said support, a framehaving a pair of arcuate rockers mounted upon said tracks for limitedrocking movementthereupon, means for preventing slipping of said framerelative to said tracks, a tool arbor mounted on said frame coaxiallywith the axis of the arc of said rockers, said frame including membersjoining said rockers rigidly together, means on said rockers for guidingrocking movement thereof along a predetermined line upon said tracks,motor means mounted on said frame members and operatively connected tosaid arbor, said motor means rocking said frame to one limit position,and means for rocking said frame to a second limit position, said toolarbor -being guided along a predetermined straight line solely byengagement of said rockers on said tracks.

OMER MOORE.

